There is something so exciting about coming here no matter the event. I always get pumped up for them, be it concerts or sporting events.
The ACC is in a great central location very close to MANY restaurants which are great for a pre-game/concert meal. It's easily accessible from Union and you don't even need to trek outside the station as they're attached (perfect for those chilly and/or intensely cold nights aka Winter 2013/2014). I've never had to park here for an event but I imagine it wouldn't be cheap. Public transportation is the best and easiest way to reach it.
The centre is very clean and well-maintained and has great service. Quick security checks before entering happen and all employees are very friendly even after passing through thousands of ticketholders. I've sat in both in the upper bowl 300s and 100s before and honestly, all seats are very good. I wouldn't say that shelling out a lot more money for 100 section seats in the upper rows would be more worth it than those seats in the 300s. Save yourself the money unless you're looking for front row/second row seats. Great sound for both concerts and games (MUCH better concert sound than the Rogers Centre)
Food and drink are what will kill your budget. Try coming on a full stomach so you aren't drooling at the sight of any quick food or drink options. There are servers in the 100 section (at least during the games) but be warned: one beer will leave you about $15 poorer. Water...about $5 and they remove the cap. *sad face*
Overall a great entertainment venue downtown!